Cita APA

Johnsgard, P. A. (1978). Ducks, geese, and swans of the world. London: University of Nebraska Press.

Citación estilo Chicago

Johnsgard, Paul A. Ducks, Geese, and Swans of the World. London: University of Nebraska Press, 1978.

Cita MLA

Johnsgard, Paul A. Ducks, Geese, and Swans of the World. London: University of Nebraska Press, 1978.

Precaución: Estas citas no son 100% exactas.